Ideas worth spreading

Playlist

Unsolved mysteries

We all love parsing the twists and folds of a good old-fashioned mystery -- of all kinds.

The mystery box

J.J. Abrams traces his love for the unseen mystery –- a passion that's evident in his films and TV shows, including Lost, Star Trek and the upcoming Star Wars VII -- back to its magical beginnings.

The Museum of Four in the Morning

Beware: Rives has a contagious obsession with 4 a.m. At TED2007, the poet shared what was then a minor fixation with a time that kept popping up everywhere. After the talk, emails starting pouring in with an avalanche of hilarious references—from the cover of "Crochet Today!" magazine to the opening scene of "The Metamorphosis." A lyrical peek into his Museum of Four in the Morning, which overflows with treasures.

Where are all the aliens?

The universe is incredibly old, astoundingly vast and populated by trillions of planets -- so where are all the aliens? Astronomer Stephen Webb has an explanation: we're alone in the universe. In a mind-expanding talk, he spells out the remarkable barriers a planet would need to clear in order to host an extraterrestrial civilization -- and makes a case for the beauty of our potential cosmic loneliness. "The silence of the universe is shouting, 'We're the creatures who got lucky,'" Webb says.

Revealing the lost codex of Archimedes

How do you read a two-thousand-year-old manuscript that has been erased, cut up, written on and painted over? With a powerful particle accelerator, of course! Ancient books curator William Noel tells the fascinating story behind the Archimedes palimpsest, a Byzantine prayer book containing previously-unknown original writings from ancient Greek mathematician Archimedes and others.

Strange answers to the psychopath test

Is there a definitive line that divides crazy from sane? With a hair-raising delivery, Jon Ronson, author of The Psychopath Test, illuminates the gray areas between the two. (With live-mixed sound by Julian Treasure and animation by Evan Grant.)

Suzana Herculano-Houzel

What is so special about the human brain?

The human brain is puzzling -- it is curiously large given the size of our bodies, uses a tremendous amount of energy for its weight and has a bizarrely dense cerebral cortex. But: why? Neuroscientist Suzana Herculano-Houzel puts on her detective's cap and leads us through this mystery. By making "brain soup," she arrives at a startling conclusion.

Marcus du Sautoy

Symmetry, reality's riddle

The world turns on symmetry -- from the spin of subatomic particles to the dizzying beauty of an arabesque. But there's more to it than meets the eye. Here, Oxford mathematician Marcus du Sautoy offers a glimpse of the invisible numbers that marry all symmetrical objects.

Why does the universe exist?

Why is there something instead of nothing? In other words: Why does the universe exist (and why are we in it)? Philosopher and writer Jim Holt follows this question toward three possible answers. Or four. Or none.

Claron McFadden

Singing the primal mystery

"The human voice: mysterious, spontaneous, primal." With these words, soprano Claron McFadden invites us to explore the mysteries of breathing and singing, as she performs the intriguing modern song "Aria," by John Cage.